This description relates to image sensors.
Individual discrete image sensors used in digital camera applications, for example, are typically obtained from a wafer on which the sensors, formed in rows and columns, are separated by dicing the wafer. In some dicing processes, slices are made in two orthogonal directions across the wafer to form saw streets between the rows and columns of sensors. Each image sensor has an array of light-sensitive pixels usually arranged in rows and columns parallel to the rows and columns along which the sensors themselves are arranged. When the sensors are formed on the wafer, subareas that do not contain light-sensitive pixels are formed between the sensors to provide space for the dicing slice or kerf to be made without damaging the sensors. To incorporate a sensor into a circuit electrical connections are made from the circuit to interconnection contacts that are typically arranged along two or more sides of the sensor.
Image sensors are sometimes used in applications that do not include lenses between the object and the sensor, for example, in contact imaging systems such as the ones described in U.S. patent application Ser. No. 14/173,500, filed Feb. 5, 2014, and incorporated here by reference.